This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The overarching goal of this study is to demonstrate that localization related epilepsy causes reorganization of language function in children during periods critical for language development. Knowledge of language systems development and plasticity in children will be gained to the extent that disruptions in normal neural networks for language function may be attributable to epilepsy. Unlike acute and limited neuronal insults, such as head trauma and stroke, epilepsy is a chronic process with continuing but paroxysmal neuronal injury. Furthermore, patients may be identified and evaluated at the outset of the disease process so that the neuronal responses and degree of plasticity may be assessed and monitored. A secondary goal is to use functional imaging methods to identify the brain regions that can sustain "reorganized" language function. The objectives of this study are to determine 1) whether children with chronic localization related epilepsy have different language organization than normal children;2) whether children with new onset localization related epilepsy have different language organization than normal children;and 3) examine the association between extent and location of atypical language organization and age of seizure onset.